Keep exsiting behavior when using objectMapper.readTree() with empty values

FasterXML/jackson-databind#2211
- In Jackson <2.9.0 an IOException was raised
- In Jackson >=2.9.0, null is returned

Author: mpfz0r

graylog2-server/src/main/java/org/graylog/plugins/beats/Beats2Codec.java

@@ -70,16 +70,14 @@ public Message decode(@Nonnull RawMessage rawMessage) {
         final JsonNode event;
         try {
             event = objectMapper.readTree(payload);
+            if (event == null) {
+                throw new IOException("null result");
+            }
         } catch (IOException e) {
             LOG.error("Couldn't decode raw message {}", rawMessage);
             return null;
         }
 
-        // Adhere to the legacy behaviour
-        if (event == null) {
-            return null;
-        }
-
         return parseEvent(event);
     }
 

graylog2-server/src/main/java/org/graylog/plugins/pipelineprocessor/functions/json/JsonParse.java

@@ -50,7 +50,11 @@ public JsonParse(ObjectMapper objectMapper) {
     public JsonNode evaluate(FunctionArgs args, EvaluationContext context) {
         final String value = valueParam.required(args, context);
         try {
-            return objectMapper.readTree(value);
+            final JsonNode node = objectMapper.readTree(value);
+            if (node == null) {
+                throw new IOException("null result");
+            }
+            return node;
         } catch (IOException e) {
             log.warn("Unable to parse JSON", e);
         }

graylog2-server/src/main/java/org/graylog2/inputs/codecs/GelfCodec.java

@@ -45,6 +45,7 @@
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
+import java.io.IOException;
 import java.util.Iterator;
 import java.util.Map;
 
@@ -127,6 +128,9 @@ public Message decode(@Nonnull final RawMessage rawMessage) {
 
         try {
             node = objectMapper.readTree(json);
+            if (node == null) {
+                throw new IOException("null result");
+            }
         } catch (final Exception e) {
             log.error("Could not parse JSON, first 400 characters: " +
                               StringUtils.abbreviate(json, 403), e);

graylog2-server/src/main/java/org/graylog2/plugin/Tools.java

@@ -644,6 +644,9 @@ public static Optional<AbsoluteRange> extractHistogramBoundaries(final String qu
         try {
             final JsonParser jp = OBJECT_MAPPER.getFactory().createParser(query);
             final JsonNode rootNode = OBJECT_MAPPER.readTree(jp);
+            if (rootNode == null) {
+                throw new IOException("null result");
+            }
             final JsonNode timestampNode = rootNode.findValue("range").findValue("timestamp");
             final String from = elasticSearchTimeFormatToISO8601(timestampNode.findValue("from").asText());
             final String to = elasticSearchTimeFormatToISO8601(timestampNode.findValue("to").asText());